Dad's NAA - - compression test results

From my knowledge of engines, cylinders 1, 3 & 4 have good valves but leaky piston rings. Cylinder #2 may have a leaky valve too.

Tractor doesn't really do a lot of work. More for play. Runs reasonably well. What should the minimum pressure be in the cylinders? Am I approaching, in need of, or overdue for a rebuild?

Your thoughts ? Thanx !

50# oil pressure is braggin' pressures.

Is it hard to start or reasonable? Iff'n it starts eazy, then probably NO need to rebuild.

Me? I'd probably give the rings some MMO (Marvel Mystery Oil) treatment (read can lable) Others like ATF (enny brand) to un-sticky the rings. Then after 3-days of MMO treatment, I'd do 'nutter compression test, dry then wet.

Iff'n it improves compression, and you generally don't burn oil, (you'll smogg the skeeters with the MMO treatment fer'bout 1/2-hr) then based upon its starting ability, base an engine rebuild decision (kit about $500) on yer skill level and desire. Professional rebuild $2000+

Remember, those old tractors were designed for horse farmers and you can operate a computer ..... .Dell

Unless you are wanting to get 100% out of here .. she's probably fine for a light to moderate use tractor.

If oil pressue is good and she starts.. I'd be tempted to leave her alone. If you wanted to do a cheap on her.. drop in rings and do a hand lap on the valve seat that wasn't sealing well, and then drop in a new set of mains and rod bearings... remember to ream or check for ridge on cyl so you don't ruin the rings... this would be a poor mans upper and lower...

probably gain you a bit of compression, and a few psi oil pressure if it was low.. if if it was already high.. like 40+.. don't expect to see much more OP.

soundguy

soundguy

Oil gauge shows around 50 psi (assuming it is reading correctly). Have thought about re-ringing it too.

Thanx for the advice.

soundguy